Docs: Windows temp cleanup after a private server needs location eviction #514

Deleting a private server's temp folder on Windows needs the location evicted first (documented elsewhere, not at the cleanup point), and read-only git objects also block deletes.

Proposed: one line where the guide shows disposal.

Source: internal developer-experience evaluation of the 2.0.32 nightly, 2026-10-18 (finding D32-18).